Quality control of the ambulatory polygraphy using automatic analysis.

It is necessary to ensure the quality of sleep studies conducted at home given that there can be potential variations. Automatic analysis is simple and could help in an audit. The objective is to find a predictive model of visual reading using an automatic analysis of saturation and respiratory signal in order to establish a reading standard with a polygraph used at home on patients who have sleep apnea-hypopnea clinical symptoms. The analysis was carried out using the following two definitions of hypopnea: an event with a duration of >or= 10 s with a decrease of > 30% of the respiratory signal; and an event associated either with a desaturation of >or= 3% or with a desaturation of >or= 4%. A total of 189 studies were selected from a representative sample of 218 patients. Two pneumologists carried out the readings together. The agreement between the visual respiratory disturbance index (RDI) [ie, apneas plus hypopneas] for both definitions and the automatic respiratory signal analysis (ie, automatic RDI [RDIa]) or the automatic desaturation index of 3% (DI3%a) and of 4% (DI4%a) showed limits from a Bland-Altman plot that were too large. However, a multiple linear regression analysis with RDIa and DI3%a or RDIa and DI4%a presented an acceptable level of agreement with RDI for both definitions (p < 0.001; r(2) = 96.2% and 97%, respectively). The 95% confidence interval for the differences between the RDI and the model was +/- 10.1 or +/- 8.8 events per hour, so a study should be revised outside of these limits. A predictive multiple regression model that uses the automatic analysis of the oximetry and respiratory signal could establish a standard for the visual reading of polygraphy at home.

Cancer-associated differences in acetylcholinesterase activity in bronchial aspirates from patients with lung cancer.

In non-neuronal contexts, ACh (acetylcholine) is thought to be involved in the regulation of vital cell functions, such as proliferation, differentiation, apoptosis and cell-cell interaction. In airways, most cells express the non-neuronal cholinergic system, each containing a specific set of components required for synthesis, signal transduction and ACh hydrolysis. The aim of the present study was determine the expression of cholinergic system components in bronchial aspirates from control subjects and patients with lung cancer. We conducted an analysis of cholinergic components in the stored soluble and cellular fraction of bronchial aspirates from non-cancerous patients and patients diagnosed with lung cancer. The results show that the fluid secreted by human lung cells contains enough AChE (acetylcholinesterase) activity to control ACh levels. Thus these findings demonstrate that: (i) AChE activity is significantly lower in aspirates from squamous cell carcinomas; (ii) the molecular distribution of AChE in both bronchial cells and fluids consisted of amphiphilic monomers and dimers; and (iii) choline acetyltransferase, nicotinic receptors and cholinesterases are expressed in cultured human lung cells, as demonstrated by RT-PCR (reverse transcriptase-PCR). It appears that the non-neuronal cholinergic system is involved in lung physiology and lung cancer. The physiological consequences of the presence of non-neuronal ACh will depend on the particular cholinergic signalling network in each cell type. Clarifying the pathophysiological actions of ACh remains an essential task and warrants further investigation.